Time study in Industrial Engineering (RMG)
Time study is a work measurement technique for recording the time of performing a certain specific job or its element carried out under specific condition and for analyzing the data so as to obtain the time necessary for an operator to carry out at a defined rate of performance.
Time study is a method of direct observation. A trained observer watches the job and records data as the job is being performed over a number of cycles.
Time study equipment:
The stop watch in general, two types of watch are used for time study.
- Fly back
These watches may be used any of the following time scales
- Decimal minutes
- Decimal hours
Selecting the job:
- The job in question is a new one, not previously carried out (new product, component, operation or set of activities)
- A change in material or method of working has been made and a new time standard is required.
- A complaint has been received from a worker or worker’s representative about the time standard for an operation.
- A particular operation appears to be a “bottleneck” holding up subsequent operations and possibly previous operations.
- Standard times are required before an incentive scheme is introduced.
- A piece of equipment appears to be idle for an excessive time or its output is low, and it therefore becomes necessary to investigate the method of its use.
- The job needs studying as a preliminary to marking a method study, or to compare the efficiency of two proposed methods. The cost of a particular job appears to be evidenced by a pareto type of analysis.
Before starting the study, there are a number of points to be observed in relation to the approach to the worker and the job he is doing.
- Make sure the job has been method studied. Especially where the standard time is to be used for incentive purposes.
in an organisation where time study has never been used before, supervision and worker representatives should be told the reasons for the study programme and given and insight into tie study procedure.
It is good policy to ask the supervisor or workers representatives to be studied. The worker should be a competent steady person with an average rate of workig.
the worker should be told the reasons for the study. Why he has been selected and asked to work at his normal pace explaining any problems that may arise during the time the study is taken.
workers should be allowed plenty of time to settle down to new methods.
when making the study the observer should take a position where he can see the whole of the job being performed. This is generally to the side of the operator, slightly to the rear and approximately 6 feet away. No attempt should be made to carry out timing from a concealed position, without the operators knowledge or with the watch in the pocket.
the observer should take a comfortable standing position for the duration of the study.
- Rating is a technique used to assess the speed and “effectiveness” of an operator.
- Consider may take into account
- Speed of movement
- Effectiveness etc.
How accurate is rating?
Rating is subjective and relies on the skill of the observer carrying out the rating exercise and the observer’s concept of the rate of working relative to a standard of 100%.
An element is a distinct part of a specified job selected for convenient of observation. Measurement and analysis.
Breaking down the job in to elements:
- Elements should be easily identified, with definite beginnings and endings so that, once established. They can be repeatedly recognized. The point at which one element ends and another begins is called break point. Breakpoints must be decided by the work study officer when he divides the work cycle into elements.
- All breakpoints can be recognised by a sound or by a change of direction of a hand or arm.
- Elements should be as short as can be conveniently timed by a trained observer, but should not be less than 0.10 minutes and more than 0.50 minutes.
- Manual elements should be separated from machine elements for future use as synthetic data.
- Short elements should be next to long elements.
Reasons for breaking down the job into elements:
- Variations in speed, pace and effort which an operator works can be more accurately recorded over short periods of time. There could be some parts of the work-cycle with the operator performs better than others.
- The more clear-cut the item of work which is timed, separately, the more readily can an appropriate fatigue allowance be arrived at for incorporation with the element.
- To ensure that productive work is separated form unproductive work.
- To enable a detailed job specification to be produced.